170135_inorganicventures_flipping

6:6 Container Transpiration

Summary of findings:

§ Transpira(on occurs around the bo2le opening and not through the bo2le as previously thought. § Taping the bo2le has no influence upon the transpira(on rate. § Bo2les that are par(ally full and opened periodically have the highest transpira(on rate. § Opening the bo2le periodically greatly increases the transpira(on rate. § Smaller bo2les transpire faster. § 30 ml bo2les can not have a 1 year expira(on date if cer(fied to an uncertainty of = ±0.6 % rela(ve. § Transpira(on Controlled Technology™ (TCT) 1 totally eliminates transpira(on

1. TCT - a patented technology that eliminates transpira(on loss, greatly increasing a standard's shelf life. Developed by Inorganic Ventures for the op(mal storage of standards aQer packaging.

7:1 Stability of elements at ppb concentra8on levels

Overview:

Consider the stability of acidic solu3ons of the elements. When looking at routes of instability, the trace analyst typically thinks of stability in connec3on with the concentra3on of the element. For example, when considering the stability of solu3ons at the part-per-million (ppm) concentra3on level, instability is generally caused by precipita3on forma3on or photo-reduc3on reac3ons. However, the main route of instability at the part-per-billion (ppb) level is derived from adsorp3on to the container walls. The stability of elemental solu3ons at the ppm level is more an issue of compa3bility and is addressed in detail in our Analy3cal Periodic Table. Plus, the stability of acidic elemental solu3ons is typically easy to achieve. It's difficult to imagine any route of instability for most elements. Take copper, for instance. Cu at the ppm concentra3on level in nitric acid is stable indefinitely. However, that same solu3on diluted down into the low to mid ppb concentra3on level makes the possibility of instability (caused by adsorp3on) a very real concern.